This section provides background information related to the present disclosure which is not necessarily prior art.
Passenger doors on motor vehicles are typically mounted by upper and lower door hinges to the vehicle body for swinging movement about a generally vertical pivot axis. Each door hinge typically includes a door hinge strap connected to the passenger door, a body hinge strap connected to the vehicle body, and a pivot pin arranged to pivotably connect the door hinge strap to the body hinge strap and define the pivot axis. Such swinging passenger doors (“swing doors”) have recognized issues such as, for example, when the vehicle is situated on an inclined surface and the swing door either opens too far or swings shut due to the unbalanced weight of the door. To address this issue, most passenger doors have some type of detent or check mechanism integrated into at least one of the door hinges that functions to inhibit uncontrolled swinging movement of the door by positively locating and holding the door in one or more mid-travel positions in addition to a fully-open position. In some high-end vehicles, the door hinge may include an infinite door check mechanism which allows the door to be opened and held in check at any desired open position. One advantage of passenger doors equipped with door hinges having an infinite door check mechanism is that the door can be located and held in any position to avoid contact with adjacent vehicles or structures.
As a further advancement, power door actuation systems have been developed which function to automatically swing the passenger door about its pivot axis between the open and closed positions. Typically, power door actuation systems include a power-operated device such as, for example, an electric motor and a rotary-to-linear conversion device that are operable for converting the rotary output of the electric motor into translational movement of an extensible member. The electric motor and the conversion device are typically mounted inside the passenger door and the distal end of the extensible member is fixedly secured to the vehicle body. One example of such a power door actuation system is shown in commonly-owned U.S. Pat. No. 9,174,517 which discloses use of a rotary-to-linear conversion device having an externally-threaded leadscrew coaxially aligned with and fixed to an output shaft of an electric motor so as to be rotatively driven thereby with an internally-threaded drive nut meshingly engaged with the leadscrew for translation along the rotating leadscrew and to which the extensible member is attached. Accordingly, control over the speed and direction of rotation of the leadscrew results in control over the speed and direction of translational movement of the drive nut and the extensible member for controlling swinging movement of the passenger door between its open and closed positions.
While such power door actuation systems function satisfactorily for their intended purpose, one recognized drawback relates to their packaging requirements. Specifically, since power door actuation systems rely on linear motion of the extensible member, the electric motor and conversion device must necessarily be packaged in a generally horizontal orientation within the passenger door and with respect to at least one of the door hinges, and with the leadscrew and output shaft of the motor being fixed in coaxial relation with one another, ample space must be provided to accommodate the rather lengthy system. As such, the application of such conventional power door actuation systems may be limited, particularly to only those vehicular doors where such an orientation would not cause interference with existing hardware and mechanisms such as for example, the glass window function, the power wiring and harnesses, and the like. Put another way, the size of known power door actuation systems coupled with the translational motion of the nut and extensible member fixed thereto requires the availability of a significant amount of internal space within the cavity of the passenger door.
In view of the above, there remains a need to develop alternative power door actuation systems which address and overcome packaging limitations associated with known power door actuation systems as well as to provide increased applicability while reducing cost and complexity.